IMF effect on ionospheric trough occurrence at equinoxes

摘要: Previous observations have shown that there is a relationship between the F region trough and both Bz By components of interplanetary magnetic field (IMF). Since IMF governs polar cap convection, we investigate here if this can be explained by means convection. The study limited to equinox seasons. poleward equatorward edges are determined from satellite tomographic their locations plotted in coordinates together with convection pattern given Papitashvili Rich [Papitashvili, V.O., Rich, F.J. High-latitude ionospheric models derived DMSP ion drift parameterized strength direction. J. Geophys. Res. 107, 2002, doi:10.1029/2001JA000264] using measurements coincident observations. results indicate close troughs Most seen within dusk cell rotates pattern, when changes its sign. More dayside observed negative than opposite case, i.e. fast convective flow favours occurrence. Nightside more frequently negative. In evening morning sectors situated cells, which partly contradicts previous showing associated reversal. It concluded plasma has an important role generation, although effect strong electric other mechanisms like precipitation certainly own.